1. Field of the Invention
The present invention relates in general to a digital broadcast signal reproducing system and method thereof, and more particularly, to a digital broadcast signal reproducing system having a digital broadcast signal receiving unit and a broadcast signal reproducing method using the system, which can be used regardless of the kinds of a broadcast signal.
2. Description of the Related Art
Generally, a broadcast signal receiving card is employed for reproducing a broadcast signal through a computer system.
Most of the broadcast signal receiving cards have the same configuration regardless of whether the broadcast signal receiving card receives an analog signal or a digital signal. The broadcast signal receiving card is comprised of a tuner for receiving a broadcast signal responding to a selected channel, an IF (Intermediate Frequency) filter converting the broadcast signal selected by the tuner to be within an IF band, a demodulator demodulating the broadcast signal outputted from the IF filter, and a decoder decoding both a video signal and an audio signal from the broadcast signal demodulated by the demodulator.
Further, there are various methods of reproducing the broadcast signal. A PCI (peripheral component interface) method is widely used In the PCI method, the broadcast signal receiving card converts the broadcast signal into a digital signal, and outputs the digital signal to a memory of a graphic card through a PCI bus. Device drivers are provided in the computer system for operating hardware components, and particularly a device driver of the broadcast signal receiving card detects the broadcast signal receiving card for an operating system, and drives the broadcast signal receiving card to output the video and audio signals from the digital signal received through the PCI bus to the graphic card and a sound card, respectively.
Recently, a broadcast signal receiving card, which can be used for a digital broadcast, is being developed in line with a digital broadcasting service. Representative examples of a broadcasting mode for the digital broadcast include, an ATSC (advanced television standard committee) mode, which was chosen in North America, and a DVB (digital video broadcast) mode, which was chosen in Europe. However, the ATSC mode and the DVB mode are different in the IF bands thereof. Further, in the case of the same DVB modes, IF bands are somewhat different.
Therefore, the computer system must have a different broadcast signal receiving card comprising a demodulator and a decoder suitable for the broadcasting mode depending on a locality. That is, the broadcast signal receiving card should be adaptable in response to either the ATSC mode or the DVB mode.
Accordingly, a lot of time and effort is required to develop a demodulator and a decoder, which is suitable for a broadcasting mode. Also to replace the broadcast signal receiving card with a new one whenever the computer system is used in places with a different broadcasting mode is uneconomical.
Consequently, development of a broadcast signal receiving card, which can be used regardless of the broadcasting mode, is needed.